LibWasm: Do not allow self-referencial globals

This is written in a somewhat roundabout way in the spec, so the
initial implementation did not implement it correctly.

Userland/Libraries/LibWasm/AbstractMachine/Validator.h

@@ -334,6 +334,7 @@ private:
     Vector<ChildScopeKind> m_entered_scopes;
     Vector<BlockDetails> m_block_details;
     Vector<FunctionType> m_entered_blocks;
+    Vector<GlobalType> m_globals_without_internal_globals;
 };
 
 }